Internally insulated and waterproofed structure



, Feb. lfl, 1936. H. voN FoRsTER 2,030,417

INTERNALLY INSULATED AND WATERPROOFED STRUCTURE Filed Feb. l0, 1954 as m1,"

NVENTOR Him/mn von f'ons'c BY G' ATTORNEY Patented Feb, Il, 1936 Unirse etres smear ortica NTERNALLY lNULATED WATER- PROOFEE? STRUCTURE Application February It, 1934, Seriai No. '110,608 In Germanyf July 21, 193% 12 Claims., (Cl. I2-427) The present invention relates to an insulatedand waterproofed structure.

It is well known that structures permeable to water, such as brickwork, concrete or stone bridges, tunnels, foundations of buildings, dams, brick reservoirs, tanks and containers and the like must be protected against water. Ground water practically always contains corrosive agents including mineral acids, carbonio lacid, humus acid, salts, alkalis, and the like, which attack brickwork, stone, concrete, and especially mortar and which, in the course of time, lixiviate or dissolve substances therefrom. This deteriorating action can be observed, for instance, in tunnels or on concrete bridges from or in connection with which, in the course of years, the foregoing lixiviation extracts and/or erodes material and causes the deposition of limestone, such as in. `the form of stalactites. Attempts have already 2o been made to prevent this deterioration by covff ering concrete or brickwork with or without'the utilization of roofing paper or boards,lead :foil or a combination thereof. It. has also been proposed to place between two` insulating layers made of asphalt, tar, asphalt board or the like, perforated aluminum sheets, whichwould in all cases absorb or take up tensile stresses in order to prevent the tearing of the insulating layer proper and the subsequent leakage of the strncture. It has been demonstrated, however, that the 'proposed coatings or .layers have not been wholly satisfactory Y'and successful in actual practice. Experience has shown that these insulating or coating layers deteriorated within ten to fifteen 36 years and that the deterioration of the concrete then started. It has then been necessary to tear up the entire road, for instance, in bridges, and

toapply a new insulation layer. This renewal 4 has, of course, been very expensive. Even more 40 troublesome has the effect of such deterioration been in tunnels in which the entire brickwork has had to be torn olf and newly built.

The present invention avoids the foregoing disadvantages and provides an insulationV or coating which permanently and reliably insulates and waterproofs a structure against water.

For this purpose one pastes on or applies to the concrete, brickwork, or the like, thin but ductile and foldable metal strips, preferably about 0.1-0.7 mm. thick, of a suitable corrossion-resistant metal or alloys, such as copper, nickel,` or other alloys thereof, by means of -an adhesive substance which remains plastic and elastic under the prevailing temperatures and other conditions. The thickness of the corrosion resistant sheet may vary depending upon the kind of construction the stresses involved, the type of metal or alloy, and the like, as those skilled in the art will readily understand. The edges of the individual sheets, which may be conveniently pro- 5 vided in the form of rolled strips in order to avoid transverse seams, are connected to each other by folding, preferably double folding. In connecting adjacent sheets to each other, soldering, Welding, pasting or any other appropriate operation may be employed. On the thus prepared, waterproof metal sheet, a layer of the adhesive substance or a combination of an adhesivev substance with a paper or board or the like is applied, in order to protect the thin metal skin or sheet against rupture or breakage by the mechanical actions of stones of the concrete or of the road lining or the like. The waterproof metal skin or sheet, permanently protects the brickwork or concrete against the penetration of Water. The adhesive substance which is between the concrete and the metal skin or sheet prevents the occurrence of water condensate resulting from sweating, secretions from concrete, or the like, which might destroy the sheet. Furthermore, due to the intimate adhesion and to the shock-absorbing nature of the adhesive substance, the metal sheet is substantially free from vibrations. In railroad bridges and tunnels, where vibrations are especiallyv liable to occur, the vibrations can 30 only be transmitted to the sheet in the form of greatly subdued oscillations due to the intermediate adhesive layer which Aremains plastic and elastic and which damps and absorbs the oscillations and renders them, harmless. Anymovement or the like of the concrete or brickwork in no way impairs the metal skin because the folds or joint betwen adjacent strips or sheets permits expansion, contraction and/or slight shifting. It has already been known in practice Y to paste or coat on wood or concrete roofs, exposed Walls and the like, thin metalstrips by means of an adhesive-mass which remains plastic. These precautions, however, were only taken when it was desired to protect exposedsurfaces against the influences of weather and when the moisture could run off freely. Wherever effective water pressure appeared and heavy mechanical stresses occurred, the tough asphalt in form of thicklayers of asphalt board with o1" Without inlayings of 5o A lead foil, aluminum sheets, etc., was considered the only satisfactory insulation material. Surprisingly, it appeared, however, that metal strips, practically as thin as foil were elastic enough and were capable by themselves of insulatingthe.V 5s

structurev against strong water pressure, while at the same time withstanding the effect of heavy mechanical influences, shocks and the like. In this manner, the present internal insulating layers show entirely different features and properties from the known roofing material, when they are associated with unbroken surfaces and they are t protected against direct shocks by envelopingl protective layers.

For the purpose of giving those skilled in the art a better understanding of the invention the following description is given of an illustrative embodiment of the invention in the form of a concrete floor of a structure like a bridge which is illustrated in the accompanying drawing, in which:-

Fig. 1 is a plan view of a structure embodying the present invention;`

Fig. 2 depicts a sectional view taken'of the line 2-2 of Fig. 1 looking in the direction of the arrows; and

Fig."3 illustrates on an enlarged and exaggerated scale, a joint between adjacent metal strips and the enveloping protective layers.

In the drawing the reference character A designates a concrete floor of a structure like a bridge. Upon the surface of .the bridge is a conventional stone road bed B laid upon a layer of gravel C. Between the bottom of the gravel layer andthe top of the concrete floor, an insulating layer including a layer of bitumen or asphalt D completely fills the space. In practice it has been found that a layer of bitumen having a thickness of about 1 to about 5 mm. gives satisfactory results. Various bitumens or asphalts may be used but it has been found that natural oil bitumen with a softening point around KS (according the Kramer-Sarnow) and/or Mexican petroleum bitumen have given satisfactory results. The softening points of the bitumen or asphalt may range from about 35-45 C. to about 80-90 C.

As those skilled in the art know, the Kramer- Sarnow method of determining thev softening point of bitumen or asphalt involves filling a glass tube 6 mm1 in diameter to a height of 5 mm. with the bitumen to be tested and filling 5 grams of mercury on top of the bitumen. Thereafter,

the tube is slowly heated in a water bath until the mercury breaks through the softened bitumen ,and runs down the glass tube. The temperature read at this moment is the softening point of the bitumen.

i Within the layer of asphalt, a series of metal rstrips E-I, E-2, E-3, E--n are provided. Each stripV has at one edge a plain U-shaped joint V and at the other edge a raised U-shaped joint W. The joint V of one strip is designed to fit into the joint W of the adjacent strip. To insure a fluidtight joint, bitumen or asphalt is packed between the joints V and W. Of course, any other suitable` sealing or cementing material having the .properties of the bitumen, asphalt, etc, referred vention provides an adhesive substance which "always remains elastic and plastic at all prevailing temperatures to which the structure is subjected. The adhesive substance is applied preferably in a hot liquid form, so that the metal skin stretches smoothly and evenly on the supports after the adhesive substance has cooled off and set. Naturally, the adhesive resistances of the supports, especially of concrete, can be improved lf the support is pre-treated before the hot adhesive substance is put on. For instance, the surface of the support can be covered with bitumen to bind the dust and moisture. In addition a layer of fibrous material can be applied to the bitumen coating. This latter procedure is advisable especially in the winter in order to prevent the hot adhesive substance from setting too quickly. In like manner the metal strips can be pre-treated with bitumen, etc. on one or both sides. 'I'his work, if desired, can partly be undertaken in the workshop where the strips are prepared.

A considerable improvement of the process according to the present invention is likewise achieved when the folds, which connect the individual metal sheets with each other, are made capillary proof by suitable means. In this manner deteriorating work which is caused by the electro-chemical reactions in the folds ismade impossible and in this manner a permanent insulation is provided. A further advantage is that the folds are -fiuid tight even under high water pressures. This precaution of capillary proof joints is always recommended when high pressure of saturating water isinvolved, such as, fr instance, in dams or in brckwork for liquids.

Sealing of the fold by tin soldering or the like is generally not recommended, aside from its high price, for the reason that under the influence of moisture,.soldering substances in contact with copper cause detrimental electro-chemical reactions to occur.` Furthermore, tin solder -falls apart under a constant low temperature as would be the case in the present instance of a bridge. 'Ihe present invention avoids the foregoing disadvantages because the folded edges are covered with an insulating substance which in inert to the metal and cannot be dissolved. It is to be noted that the invention uses for this purpose the same plastic and elastic adhesive substance which is used to mount the metal `sheets in the structure. In this manner, the folded edges of both metal sheets are connected with each other by a fluid-tight and spaceless joint, so that penetration of moisture is prevented. Naturally, for the-packing of the fold or joint, it is also possible to use an adhesive substance in a suitable solution. For instance, the bitumen may be dissolved in a paran oil and applied as a cold layer. In this manner an exceptionally convenient operation is afforded. It has been unexpectedly found that folds or joints packed in the foregoing manner permanently resist water pressure.

It is'to be observed that the present invention provides an insulated and waterproofed layer for constructions above and under ground including bridges, tunnels, foundations of buildings, dams, reservoirs, tanks and the like made of concrete, masonry, brckwork and the like comprising a plurality of the corrosion resistant metallic v'sheets connected together, preferably in overlapping relation and capable of being elongated, stretched, contracted and rolled, and an intermediary layer of an adhesive substance interposed between each side of the aforesaid sheet and the adjacent surface of the construction to be protected, said adhesive substance being adapted to remain plastic and elastic at the pre/1 va-iling temperatures to which the constructions are exposed 0. A

It is also to be noted that the invention provides an insulated and waterproofed layer to be internally incorporated in structures comprising a plurality of corrosion resistant metallic sheets which may be joined lengthwise or crosswise, de-

pending upon the slope and drainage of the road. which may be polished, and which may be corrugated.

y Furthermore, it is to be observed that the present invention provides an insulated and Waterproofed layer for internal incorporation in brickwork, concrete and masonry constructions for protecting the latter against moisture permeating the capillary pores and for providing resistance againstchemical reactions or influences in the cement, mortar, or the like.

Although the present invention has'been described in connection with preferred embodiments, it is tov be understood that variations and modifications may be resorted to by those skilled in the art. Thus, in place of using bitumen or asphalt which is applied in a hot condition, cold applications of bitumen or asphalt dissolved in solvents such as parain oil; etc. may be used. Similarly, corrugated metallic sheets may be used in place of smooth sheets. In addition, a lining of fibrous material, such as paper, may be applied to and pasted or cemented on' one or both of the outer surfaces of the bitumen layer.- Moreover, instead of the interlocking joint, the strips may be connected with each other by overlapping their longitudinal edges with the interposition of a cementing layer of bitumen or the like. it has been found that satisfactory results may be obtained in the foregoing manner even without the interlocking joint.

I claim:-

l. An insulated and waterproofed layer for constructions above and underground including bridges, tunnels, foundations of buildings, dams, containers which comprises a plurality of long, foldable and corrosion-resistant metallic sheets of foil thickness connected together and capable of expanding and contracting and of remaining flexible and elastic, said sheets being thin enough toy be ductile and to conform to elevations andl -depressions of the surrounding structural memstance being adapted to remain plastic and elastic at atmospheric temperatures, to absorb shocks, and to prevent the occurrence of condensates on the surfaces of said metallic sheets.

2. An insulated and waterproofed layer as set forth in claim 1 in which the ends of the adja- Yjacent; sheets are turned vin and are interlocked within each other.

3. An insulated and water-proofed layer as set forth in claim 1 in which the joints of the adjasdams and the like which comprises a plurality of members of the structure having a small space therebetween, and an insulating and waterproofing layer provided in said space and comprising a plurality of long, foldable and corrosion-resistant metallic sheets of foil thickness connected together, said sheets being thin enough to be ductile and to conform to elevations and depressions of the surrounding structural members and having suicient mechanical strength to resist penetration of said structure and being separated from the parts of the structure by a layer of adhesive substance which remains plastic and elastic at atmospheric temperatures and which absorbs shocks and prevents the occurrence of condenv sates on the surfaces of said metallic sheets.

6. An insulated and waterproofed structure including bridges, tunnels, foundations of buildings, dams and the like which comprises a plurality of members of the structure made of concrete, stonework, masonry and brickwork and having a small space therebetween, and an insulating and waterproofing layer provided in said space and comprising a plurality of long, foldableand corrosion-resistant metallic sheets of foil thickness connected together, said sheets being thin enough to be ductile and to conform to elevations and depresions of the surrounding structural members and having sufficient mechanical strength to resist penetration of said structure and. separated from the parts of the structure by'a layer of a bituminous adhesive substance having a softening point ranging from about C. to about 90 C. which remains plasticand elastic at atmospheric temperatures and which absorbs shocks and prevents the occurrence of condensates on the surfaces of said metallic sheets.

7. An 'insulated and Waterproofed structure including-bridges, tunnels, foundations of buildings, dams and the like which comprises a pluraliuty of members of the structure made of concrete,

' stonework, masonry and brickwork and having a small space therebetween, and an insulating and Waterproofing layer provided in said space and comprising a plurality of long, foldable and corrosion-resistant metallic sheets of foil thickness connected together, said sheets being thin enough s to be ductile and towconform to elevations and depressions of the surrounding structural memvbersand having suiiicient mechanical strength to resist penetration of said structure, and separated from the parts of the structure by a layer of a natural oil bitumen adhesive substance having a softening point of about 65 KS which remains plastic and elastic at atmospheric temperatures and which absorbs shocks and prevents the occurrence of condensates on the surfaces of said metallic sheets.

8. An insulated and Waterproofed structure including bridges, tunnels, foundations of buildings, dams and the like `which comprises a plurality of members of the structure having a small space therebetween and an insulating and waterproofing layer provided in said space and comprising a plurality of long, foldable and corrosionresistant metallic sheets of about 0.1 mm. and

y together, said sheets being thin enough to be ductile and to conform to elevations and depressions of the surrounding structural members and having suilicient mechanical strength to resist penetration of said structure, and being separated from the parts of thefstructure by a layer of adhesive substance which remains plastic and elastic at atmospheric temperatures and which absorbs shocks and prevents the occurbelow to about 0.7 mm. in thickness connected/" rence of condensates on the surfaces of said metallic sheets.

9. An insulated and waterprooie-d structure including bridges, tunnels, foundations of buildings, dams and the like which comprises a plurality of memberscf the structure having a small space therebetween, and an insulating and waterproong layer provided in said space and comprising a plurality of long, foldable and corrosionresistant metallic sheets of foil thickness connected together, said sheets being thin enough to be Aductile and to conform to elevations and depressions of the surrounding structural members and having suicient mechanical strength to resist penetration of said structure and being separated from the parts of the structure by a layer of adhesive substance having a thickness of about 1.0 mm. to about 5.0 mm. which remains plastic and elastic at atmospheric temperatures andf which absorbs shocks and prevents the occurrence of condensates on the surf-aces of said metallic sheets.

10. An insulated and waterproo'ed structure including bridges, tunnels, foundations of buildings, dams and the like which comprises a plurality of members of the structure having a small space therebetween, and an insulating and waterproong layer provided in said space and comprising a plurality of long,ioldable and corrosionresistant metallic sheets of foil thickness connected together, said sheets being thin enough to be ductle and to conform to elevations and depressions of the surrounding structural members and having sufficient mechanical strength to resist penetration of said structure and being separated from the parts of the structure by a layer of adhesive substance containing fillers of the group consisting of steel wo'ol, asbestos fibres and glass wool, which adhesive substance remains plastic and elastic at atmospheric temperatures and which absorbs shocks and prevents the oc conform to elevations and depressions of the surrounding structural members and having sumcient mechanical strength to resist penetration of said structure and being separated from partsy of the structure by a layer of adhesive substance which remains plastic and elastic at atmospheric temperatures and which absorbs shocks and prevents the occurence of condensates on the surfaces of said metal sheets.

12. An insulated and waterproong structure 1 including bridges, tunnels, foundations of buildings, dams and the like which comprises a plurality of members of the structure having a small space therebetween, and an insulating and waterproong layer provided in said space and comprising a plurality of long, foldable sheets of a copper-containing metal of foil thickness connected together, said metal sheets being thin enough to be ductile and to conform to elevations and depressions of the surrounding structural members and having suicient mechanical strength to resist penetration of said structure and being separated from the parts of the structure by a layer of adhesive substance which remains plastic and elastic at atmospheric temperatures and which absorbs shocks and prevents the occurrence of condensates on the surfaces of said metal sheets.

HERMANN voN FORSTER. 

